SUMMARY The purpose of the Lipidomics Core in the PPG is to provide intellectual and physical resources (particularly state-of-the-art mass spectrometry analysis of sphingolipids and synthetic molecular tools) to enhance understanding of the role of bioactive lipids in cancer biology with the goal to discover future therapeutics. The diversity of bioactive lipids and their interconnected metabolism generates a network of pathways regulating intra- and inter-cellular signaling and function. Dysfunctions in these pathways contribute to the pathobiology of cancer progression and metastasis. These considerations have necessitated the development of lipid chemistry and analysis. The Lipidomics Core was created based on unique expertise of the key personnel in lipid chemistry, analysis, and metabolism. This Core has developed into an institutional, national, and international resource in the emerging fields of lipidomics and lipid chemical biology. Core services include: 1) Providing qualitative and quantitative analysis of lipid components from different biological materials (cells, tissue, and biological fluids), primarily employing high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technology?the Core currently provides quantitative analysis of more than 300 distinct lipid molecular species at a basic metabolomic level; 2) Developing and providing synthetic molecular tools to study lipid metabolism (e.g., functionalized and fluorescent ceramides, site-specific radioactive sphingolipids, 17C-sphingolipids) and diversified synthetic lipids and analogs for cellular, in vitro, and in vivo studies (e.g., organelle-targeted sphingolipids and organelle-targeted inhibitors of sphingolipid metabolizing enzymes); 3) Providing direct MALDI-MS tissue analysis to visualize the distribution of lipid based anti-cancer drugs and their molecular effects on sphingolipid components; and 4) Assisting PPG investigators in experimental design, selection of lipids of interest, and interpretation of analytical results.